Improving Performance of Wireless Ad Hoc Networks Using a Few Point-to-Point Links

The current wireless technologies such as IEEE 802.11 (Wi-Fi) make ad hoc networking viable for small regions involving a few tens of mobile nodes, but such networks are unreliable. In this paper, we investigate the benefits of adding a few infrastructure nodes to an otherwise ad hoc network. These infrastructure nodes are interconnected among themselves with point-to-point (p2p) links in addition to Wi-Fi capability. We simulated small ad hoc and mixed networks with 50 mobile nodes and 9 fixed nodes with 12 wired links among them in a 1.5 × 1.5 Km2 field. The 9 fixed nodes form a 3 × 3 grid in the middle of the field. We tested mixed and ad hoc networks for UDP and TCP traffic patterns. Our results show that mixed networks outperform ad hoc networks by providing 50-100% higher throughput and 50% lower average delay. The primary reasons for significantly higher performance are increased route stability even with a small number of wired links and less contention for wireless channels.